Photographic color development employing pyrazoline compounds



United States Patent IO PHOTOGRAPHIC COLOR DEVELOPMENT EMPLOYING PYRAZOLINE COMPOUNDS No Drawing. Application July 7, 1955 Serial No. 520,607

. Claims priority, application Germany July 8, 1954 2 Claims. CI. 96-55) The present invention relates to a process for the production of photographic color images by color developmentand especially to such a process in which special combinations of developing substances are used.

' In the production of color images by color development of exposed silver halide emulsion layers, a colored image is formed in addition to the silver image, due to the development product of the developer reacting with color couplers simultaneously present to form a dyestulf. Those processes in which p-phenylene diamine or its derivatives are used as developer have acquired particular importance in practice. p-Aminophenol and its derivatives have also been described for this purpose. Moreover, 4-aminopyrazolones have been described as colordeveloping substances in copending application Serial No. 493,044, filed March 8, 1955. 'As color couplers, there may be used a large number of compounds which yield quinonimine or azomethine dyestufis in exposed silver halide emulsion layers in the presence of the aforementioned color developers, such compounds being, for example, phenols, naphthols, aromatic amino compounds, indazolones, andalso substances. with active methylene groups, suchas derivatives ,of acylacetic acid esters and pyrazolones. N

It has now been found that in color development, it is advantageous to use, in addition to color-developing substances, l-(p-aminophenyl)-3-aminopyrazoline and also its derivatives, in which the hydrogen atoms of the pamino group in the l-phenyl radical and/or of the 1- phenyl radical itself are replaced by at least one substituent. "Assubstituents, there may be considered, for example, alkyl, aralkyl, aryl, acyl, halogen, alkoxy radicals. By way of example there may be cited the following compounds: 1-p-methylaminophenyl-3-aminopyrazoline, 1 p methanesulfonylaminophenyl 3 aminopyrazoline, 1 (4 ethylamino 3' methylphenyl 3- aminopyrazoline. The color development is influenced in an extraordinarily favourable manner by this addition of l-(p-aminophenyl)-3-aminopyrazolines, and there are found very valuable superadditive effects from the conjunction of the two compounds, which cannot be produced by the color-developing substances by themselves. The l-(p-aminophenyl)-3-aminopyrazolines which are substituted in the amino residue are themselves not to be considered as color developers, whereas those compounds act as color developers when they are not substituted in the amino residue.

.According tothe present invention, the color development is intensified in that the same color intensities and the same color gradations are obtained, for example,-

with smaller amounts of. developing substances or in shorter development times when using a constant concentration. On the other hand, this process may be used in order substantially to raise the a-values of the color gradation or to increase the sensitivity of the photographic material- The process according to the invention not only enables the processing times to be shortened or made less costly because a smaller amount of color developer substances are used, but also results in an improvement in the quality of the color material, to which particular value is attached because of the fact that with a constant photographic material, there is obtained a large range of variation as regards the a -values, so that, for example, a pre determined positive material may be adapted to quite diflFerent types of negatives simply by development.

The super-additive effect already occurs with very small quantities of the activating compounds. Usually only 1-10 percent by weight, calculated on the color developer substance,- are sufiicient to produce the desired efiect, that is to say that the concentration of the pyrazolines per 1000 cc. of water usually amounts to about 50-500 mg., although other concentrations may also be used.

The substitution products, in which the hydrogen atoms of the l-phenyl nucleus or the heterocyclic ring are substituted, also behave in the same way as the said 1-(paminophenyl) -3 -aminopyrazo1ines.

The 1-(p-aminophenyl)-3-aminopyrazolines may be added to the colour developer solution or may also be incorporated in the photographic layers to be developed.

The l-p-aminophenyl)-3aminopyrazoline may be obtained by l-(p-acylarninophenyl)-3-aminopyrazolines, such as, for example, the acetyl derivative, being saponified with alkali. The derivatives of this compound may be prepared in analogous manner. (Furthermore, there may be applied the process disclosed in the copending application Serial No. 440,562, filed June 30, 1954, and now abandoned.)

Example 1 4-amino-ethyl-hydroxyethyl aniline g 5 Potassium carbonate g Sodium sulphite g 3 Water 1itres 1 With a development time of 7 minutes at 18 C., there is produced an average gamma of 0.7. The relative sensitivity which is obtained is 1.0.

If 0.2 g. of 1-(4'-methyl sulphamidophenyl)-3-aminopyrazoline is added to a developer of the above composition, a'gamma of 0.9 and a relative sensitivity of 2.0 are obtained under the same conditions. For the preparation of this compound Example 7 of copending application Serial No. 440,562 gives the following instructions: 1 mol of N-nitroso-N-(p-methanesulfonylaminophenyl)-}3-aminopropionitrile is introduced together with 200 grams of zinc dust into 2 liters of 10% acetic acid. When the reduction is complete the zinc slurry is filtered off with suction and washed with hot acetic acid. The filtrate is supersaturated with acetic acid, whereby 1-(4'- color is developed in a developer of the following com position:

4-amino-diethylaniline g 2 Potassium carbonate g 70 Potassium bromide g 2 Sodium sulphite g 3 Water litres 1 With a developing time of 10 minutes at 18 C. a gamma equal to 1.8 is produced with a relative sensitivity equal to 1. If 0.15 g. of 1-(4-methylaminophen yl)- 3-aminopyrazoline chloride is added to a developer of the above composition, the gamma under the same conditions rises from 1.8 to 2.0. The relative sensitivity is then 1.7. The l-(p-methylaminophenyl)-3 amino-pyrazoline is obtained by refluxing 23.2 grams of 1-(p-acetomethylaminophenyl) 3 aminopyrazoline (M.P. 263 C.) with 270 ml. of 10% aqueous sodium hydroxide solution for 10 hours and cooling the reaction mass. The first-mentioned compound crystallizes out, and is converted into the hydrochloride by one of the customary methods.

Example 3 An exposed black-and-white negative film is developed in a developer of the following composition:

4-amino-ethyl-hydroxyethyl aniline g 5 Potassium carbonate g 70 Potassium bromide g 2 Sodium sulphite g 3 Water .litres 1 1 hydroxy-4-sulpho-2-naphthoic acid anilide g 0.6

With a development time of minutes at 18 0., there is obtained a blue-green color image with a gamma of 0.6 and a relative sensitivity equal to 1.

If 0.25 g. of l-(4-acetylaminophenyl) 3 aminopyrazoline is added to a developer of the above composition, a gamma equal to 0.8 is produced with a relative sensitivity equal to 1. (For the preparation of this substance s'ee British specification 679,678, Example 14.)

Example 4 color coupler is developed in a developer of the following decomposition:

4-amino-diethylaniline g 2 Potassium carbonate g 70 Sodium sulphite i g 3 Potassium bromide l. g. 2 Water Q litr'es" 1 With a development time of 6 minutes and 18 6. there is obtained a gamma equal to 0.7 and a relative sensitivity equal to 1. If 0.5g. of 1-(4 -methanes ulfonylamino-3'rethoxyphenyl)-3-aminopyrazoline is added to a developer of the above composition a gamma of 1.0 and relative sensitivity of 1.5 are produced.

4 Example 6 An exposed subtractive multi-layer color negative film having incorporated components is developed in a developer of the following compositions:

4-amino-diethylaniline 2 Potassium carbonate g 70 Sodium sulphite g-.. 3 Potassium bromide g 2 Water litres 1 A e o en e of 6 mi u e and a. d velop temperatureof 18 C. is required to obtain an average gamma of 0.7 and a relative sensitivity of 1 If 0.08 g. of 1-(4'-methylaminophenyl)-3-aminopyrazoline-dihy drochloride is added to a developer of the above composition, a development time of 4 minutes only required to obtain the above said values.

Example 7 An exposed subtractive multi-layer color negative film having incorporated color components is developed in a developer of the following composition:

A development time of 6 minutes and a development temperature of 18 C. is required to obtain an average gamma of 0.7 and a relative sensitivity oi 1. If 0.25

' gfof 1-(4'-methylaminophenyl)-3-aminopyrazoline dihy drochloride is added to a developer of the above composi; tion, a development time of 3.5 minutes only is required to obtain the aforesaid values.

Example 8 An exposed subtractive multi-layer color positive film with color components in the layers is developed in a developer of the following composition:

4-amino-diethylaniline g 2 Potassium carbonate g 70 Sodium sulphite g 3 Potassium bromide g 2- Water litres" 1 tivity of 2.0 are produced.

Example 9 An exposed subtractive multi-layer color negative film with color components incorporated in the layers is developed in a developer of the following composi tion: A

to obtain an average gamma bro] and a relative sensi j tivity of 1. If 0.5 g. of 1-(4 -methanesulphonyl-3 meth ylphenyl)-3-aminopyrazoline is added to t-he developer of the above composition, the development time is "re; duced to 4.5 minutes.

Example An exposed subtractive multi-layer color negative film with color components in the layers is developed in a developer of the following composition:

A development time of 6 minutes at 18 C. is required to obtain an average gamma of 0.7 and a relative sensitivity of 1. If 0.2 g. of 1-(4'-ethylaminophenyl) -3-pyrazolindihydrochloride is added to the above developer composition a development time of 3.5 minutes is required to obtain the same values.

For the preparation of the pyrazoline derivati es disclosed in the above examples reference is also made to the copending application by Rudolf Mersch and Detlef Delfs under the title Process for the Production of l-(p- Aminophenyl)-3-Aminopyrazoline, Serial No. 515,558, filed June 14, 1955, now U.S. Patent 2,840,567, granted June 24, 1958.

What we claim is:

1. In the process for the production of photographic color images by providing a photographic silver halide layer containing a color coupler dye-forming material as well as a latent optical image and developing the latent image with an alkaline silver halide developing solution containing an amine that forms a dye with the color coupler wherever it develops the silver halide, the improvement by which the developing is carried out in the presence of an additional amine having the formula:

H R, in which R stands for a member selected from the group consisting of hydrogen, alkyl, alkoxy and halogen, and R stands for a member selected from the group consisting of hydrogen, alkylsulfamido, alkyl and acyl.

2.. A process according to claim 1 in which the additional amine is 1-(4'-aminophenyl)-3-amino pyrazoline.

References Cited in the file of this patent UNITED STATES PATENTS 2,533,514 Sawdey et al. n Dec. 12, 19 

1. IN THE PROCESS FOR THE PRODUCTION OF PHOTOGRAPHIC COLOR IMAGES BY PROVIDING A PHOTOGRAPHIC SILVER HALIDE LAYER CONTAINING A COLOR COUPLER DYE-FORMING MATERIAL AS WELL AS A LATENT OPTICAL IMAGE AND DEVELOPING THE LATENT IMAGE WITH AN ALKALINE SILVER HALIDE DEVELOPING SOLUTION CONTAINING AN AMINE THAT FORMS A DYE WITH THE COLOR COUPLER WHEREVER IT DEVELOPS THE SILVER HALIDE, THE IMPROVEMENT BY WHICH THE DEVELOPING IS CARRIED OUT IN THE PRESENCE OF AN ADDITIONAL AMINE HAVING THE FORMULA: 